Re: Squealing shower
Change the shower head.
Most shower heads these days are "water saver" heads, they have a restrictor washer in them that reduces water flow and pressure. Pull the restrictor out and no more squeal. Some shower heads the restriction is built in and must be enlarged with a drill bit. If you go this route, use a drill bit that is only slightly larger than the hole and test your work, increase the hole gradually until you have no more squeal.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!