It'll slowly diminish as he feels more comfortable - and hopefully go away once he is neutered. My Roscoe is getting fixed in two weeks, and I can't wait.
Just keep in mind that certain things may make him leave marking pellets more.... If my dogs put their head in Roscoe's crate - which they often do out of curiosity and sometimes to get him to come out and play - he sometimes will then leave pellets just across the open gate and across in front of the crate - as though to say "this is mine, stay away."
The other night, he and hubby were having a turf war. He wanted to hang out under hubby's chair when hubby had the footrest up. Hubby didn't like him being under there, worried he would forget and close it on Roscoe - so he got down there and tried to shoo Roscoe out. No luck. Ended up having to practically pull Roscoe out from underneath so hubby could close the chair. Roscoe wasn't too happy with him the rest of the night. Every time hubby would get up, Roscoe would jump up in his chair and leave some pellets. And a couple of times he did a serious nose bump and nip at hubby's sock-covered toes.
Later hubby gave him some treats, and it was all good.....