Russian tortoises do have a pretty stinky poop. But romaine isn't a very good diet for a tortoise. One way to solve your problem is to build him a safe and secure outdoor yard and move him outside.
Yes, it is a Penn Plax Tortoise Palace. Also he does not just eat Romaine, that is just what he is currently eating at the moment. I always clean up his poop & pee, yet it always smells of urine. Caesar also sometimes smells like urine & I've found the smell intensifies when I mist his enclosure... We are also in the middle of building the perfect outdoor enclosure, but we live in Massachusetts so it isn't the warmest...