Bad Dog,Bad!

My two male boston terriers(dad and son) are constantly hiking their legs on the furniture. I very seldom catch them in the act so it's hard to try and train them. I plan on getting them nipped to stop them from growling and fighting with each other but I've been told unless broke early,getting them fixed won't stop the peeing.

I need a spray or something that will repell them from "watering" the furniture or a place that still sells plastic sofas and armchairs.I read lemon and orange scents will repell them but none of the scented cleaning products are working.It's not a need to empty their bladders,it's marking territory.

Help! I want to buy new furniture but can't with them doing this. The two younger dogs(both 2yrs old) also chew up things when they get made at me.

P