Based on an obligatory precaution, it is impermissible to cause a major harm to one's body. If this does not cause a severe harm then it is permissible. In any case, we advise you to refrain from doing such things, as it is an act of frivolity. If it encourages misguidance and deviation, then it becomes prohibited.
It is not permissible to do Tayammum instead of Ghusl in the said cases as long as water is available. Our advice to you is to economize in spending water, avoid extravagance and perform Ghusl in a balanced way and without paying attention to doubts; having said that, using excessive amount of water in Ghusl does not invalidate it.
If one knows that the walls and the ceiling came in wet contact with the workers, they should be made tahir, and one can offer the prayers in the mosque.
