I don't know if this will help but...when I brought MC home from my brothers, Mau couldn't stand him, she'd growl everytime he was near and he'd hide behind things and charge her, she'd hiss and run. As a result MC would spray usually whereever she had been although sometimes he picked random spots. Mau can be aggressive so I knew I'd never find her a home and MC had been in my family since he was a kitten (he was I think 10 at the time) so I didn't have the heart to rehome him. Anyway it took a lot of patience and over a year but he's stopped spraying and they can be in the same room without trying to kill eachother. I did a few things all at once. The vet perscribed some valium which I gave for about 2 weeks (can't remember I followed what the vet listed), at the same time I purchased feliway, both a plug in for "his room" and a spray which I'd spray on a bandana I tied around his neck so he was mellow from the drug and mellow from the feliway for about 2 weeks. In addition, I'd seperate him from "the girls" He was locked in the front living room and I attempted to keep them completely seperated even when I weaned him off the drugs. Slowly for short periods I started to let them in the same room when I could keep and eye on them (I've used both a squirt bottle and thrown a toy mouse in front of him if I caught him trying to charge. (the feliway bandana still on). We went about a month with only a couple of charging episodes and no spraying the first time. When he started spraying again I gave him the drug, but this time for only a couple of days. Each time we went longer and longer until now I no longer have to give hime the drugs or use the feliway. He hasn't sprayed in about a year and the charging very rarely occures. It wasn't totaly pleasant initially (he was always sleepy kind of glazed), but I now have 3 cats that can live together without problems. Mau and MC will never be best friends, but they've learned to live together.