Lube and relaxation help?

Hey all, so I know theres a couple threads on lube and stretching.. but I heard somewhere that theres a water based lube that helps relax and dilate the inside of the anal canal but I can't seem to find it. The only thing I can find is a warming or numbing lube. Maybe I heard wrong? but if anyone knows anything please let me know! The main reason is after toying for awhile there seems to be a spot in my second wall that feels uncomfortable even during gentle play and I dont want to just straight up numb the area in case I might damage something. Poppers aren't really something I'd consider.. but I've read there might be some essential oils that can increase arousal or relax the body (not by ingesting of course).. I'd appreciate any insight or info. Thanks!