Praise be to Allah.
What is required when doing ghusl is to make the water reach every part of the body. If there is a dressing which will not cause any harm if it is removed, then it must be removed.
Ibn Qudaamah (may Allah have mercy on him) said in al-Mughni (1/173): al-Qaadi said: Regarding dressings on wounds, if removing the dressing will not cause any harm, he should remove it, then wash what is healthy and do tayammum for the wound, and he should wipe over the site of the wound. If removing the dressing will cause harm, then it comes under the same ruling as a plaster cast, and he must wipe over it. End quote.
This applies if the dressing covers a wound, so it is more likely to be the case if the dressing covers a part of the body where there is no wound.
But if removing the dressing will lead to loss of money, because its price is very high, then it is permissible to leave it and do tayammum instead, so as to ward off harm.
It says in Akhsar al-Mukhtasaraat: … or there is the fear of physical or financial harm, or any other harm, as a result of using [water] or seeking it.
He said in his commentary, which is known as Kashf al-Mukhaddiraat (1/81): Or there is the fear, as a result of using water or seeking it, of physical harm such as a wound and severe cold, or losing one’s travelling companions, or causing thirst to oneself or anyone else, whether it is a human or an animal whose life is regarded as valuable, or water is needed to make dough or cook, or it is not possible to obtain water except at a price that is much higher than the usual price for water of similar quality in that region. End quote.
Thus the scholars regarded the inflated increase in the price of water as an excuse that makes it permissible to do tayammum.
If you need to wear this device, and the price of the adhesive type is high, then when you do ghusl, you can do tayammum for the part that is covered by the tape and the water does not reach it, and you can wash the rest of the body, just as in the case where the plaster cast covers more than is needed. This is the same as that, because it is adhesive tape that is not covering a wound, and no harm will be caused by removing it, so it cannot be wiped over; rather tayammum must be done for it.
There is nothing wrong with having intercourse, even if it will lead to doing ghusl and needing to do tayammum. Many of the fuqaha’ regard it as permissible for the one who has no water available to have intercourse, and they did not regard that as being disliked (makrooh); they said that he should do tayammum.
An-Nawawi (may Allah have mercy on him) said in al-Majmoo‘ (2/209): ash-Shaafa‘i said in al-Umm, and his companions said: It is permissible for the traveller to have intercourse with his wife, even if they do not have water, and he should wash his private part and do tayammum. And our companions agreed that it is permissible to have intercourse [in this situation] and that it is not disliked (makrooh). … this is the view of our madhhab.
Ibn al-Mundhir narrated the view that it is permissible to have intercourse [in this situation] from Ibn ‘Abbaas, Jaabir ibn Zayd, al-Hasan al-Basri, Qataadah, ath-Thawri, al-Awzaa‘i, ashaab ar-ra’y, Ahmad, and Ishaaq, and this view was favoured by Ibn al-Mundhir.
It was narrated from ‘Ali ibn Abi Taalib, Ibn Mas‘ood, Ibn ‘Umar, and az-Zuhri that they said: he should not do that. It was narrated that Maalik said: I would not like him to have intercourse with his wife unless he has water with him. It was narrated that ‘Ata’ said: If there is three days’ travel between him and a source of water, he should not have intercourse with her, but if water is further away than that, then it is permissible. Two reports were narrated from Ahmad stating that it is disliked (makrooh).
Our evidence for all of that is what Ibn al-Mundhir quoted as evidence that intercourse is a permissible action, so we cannot regard it as disallowed or disliked (makrooh) except on the basis of evidence. This is the basis of our argument.
As for the hadith of ‘Amr ibn Shu ‘ayb, from his father, from his grandfather, who said: A man said: O Messenger of Allah, a man travels and he cannot find water; can he have intercourse with his wife? He said: Yes. Narrated by Ahmad in his Musnad, it is not to be used and evidence because it is a da‘eef (weak) hadith and it is the narration of al-Hajjaaj ibn Artaat, who is a weak narrator, and Allah knows best. End quote.
If that is allowed with regard to obligatory ghusl, then it is more appropriate that other types of ghusl and washing should be allowed. So there is nothing wrong with you doing a Sunnah ghusl, or taking a shower in order to clean yourself, and you do not have to refrain from any of that, because these are permissible things and you do not have to refrain from them except on the basis of evidence.
As for the secret habit (masturbation), it is haraam and must be avoided at all times, and even more so in this case. Please see the answer to question no. 329 .
And Allah knows best.