Getting him fixed would help, the best stuff I found to neutralize the odors and get rid of the smell completely is cheap and really works...Don't laugh, Massengill Douche, seriously, get a fresh clean sent double pack and put it in a spray bottle, do not dilute it, spray it on the offending smell and let it dry, do not scrub or rub it just let it dry. You may have to repeat several times (let dry in between each sprays) and it will get rid of the smell completely.

 Once a male cat starts "spraying" he will not stop; neutering will not solve your problem of the smell, but it might calm him. You should ask the vet what he would suggest to control the odor. Good luck! Keep your closets closed or your clothes/shoes/linens will be sprayed!

 See to the control of odor by deos& sprays..

 Shove him in a box, send it back to Persia, and ask Xerxes (the Persian emperor) to give you a new one that won't mess your house up with a smell.