27 posts in this thread and this is almost the only one that doesn't involve some kind of voodoo. In this thread, free advice is worth less than you're paying for it. I think I actually lost some brain cells reading some of these inane posts.
The only correct way to repair the leak is to cut and replace. You want it permanently repaired, right? You don't want to have to worry or wonder about it forever, nor do you want to have to fix it again later when the leak gets worse. If you have a leak, then you did something wrong in the assembly (it happens) or used the wrong materials. PVC needs to be joined with the correct primer/cleaner and cement, not some other magic method or material recommended by somebody on YouTube or a forum. PVC cements solvent weld the joint. Once joined, the pieces cannot be taken apart using heat or anything else short of dynamite. Anybody who tells you otherwise is a fool. Silicone sealant is not some magic material that can repair plumbing leaks, and anything else that might stop the leak is just a temporary band-aid.
Cut and remove the leaking section. If you're confident that you used the correct materials and methods, you can salvage the rest. Remake the leaking section correctly, with the correct materials, preparation, cement, and joining method. You can use straight PVC couplings to rejoin the replaced section(s) to the old. Then have a good night's sleep.
