My horse was terrified of a bridle and used to go up at the sight of one.. I got a leather headcollar and unclipped the side part and left the buckle done up...every morning and eve at turn out and bring in I put it on like a bridle.. In a week or two he was used to it and a couple of months...
I find taking out the really 'squelshy' parts and then replacing with drier 'existing' bed before adding fresh straw on top works...I also add slightly more fresh to the area where he wee's regularly! X