Need help with house training?

Sorry this is so long but I am desperate. My dog is a 19 month old female Boston Terrier. We have had her for 15 months. I have tried every bit of advice handed to me in order to get this dog to go outside. I have had her checked at the vet for abnormalities. My vet thought I was a nut but I was told she may have urinary tract or bladder issues. She is crate trained and at this point lives mainly in the crate because unless she is under 24 hour watch she will go in the house. If we are sitting in the kitchen when she has to go she will go to the door. If we are not she goes wherever she feels. Though I know she is going to the door the fact that she has to make some noise to let us know she is there isn't sinking in. I have taught her how to speak and make her speak every time i open the back door yet she will not bark to go out she just stands there. I even taught her how to ring a bell that I hung on the door handle (another piece of advice that isn't working) but unless you tell her to ring the bell or speak she will do neither when wanting to go out. Also her crate is just roomy enough for her to sleep in yet she goes in the crate. She goes on the blanket she is lying on and gets covered in pee. I have to bath her at least 3 times a week and her skin is being affected by the bathing but I have no choice. I put her water bowl down only 3 times a day for her and let her drink to control how much water she gets to no avail. If I let her sleep in the bed with us she goes on the bed. I am at my wits end. The last advice I got was and I quote "You may just have to accept the fact that she goes in the house. Some dogs never get trained. Just try and keep up with the cleaning." Is this true? I have to just let my dog use the house as a toilet and accept it? What else can I do besides keep her crated 24/7.