Capsaicin

It is natural for capsaicin creams to burn. The ingredient comes from a variety of chili pepper juice. It is often used for arthritic conditions. I doubt I would use it in the cream form for the condition you describe. There is a capsaicin patch which comes in a .025% (that's 1/40 of 1%). I use such patches with some frequency on arthritic wrists, shoulder and hip, to good effect. There are several advantages. Most significantly, it is the mildest form of capsaicin I have found. I believe in doing the least strenuous thing to get the job done. I believe this from long experience.

The disadvantage is that these patches stick quite well. If you apply them to an area with hair, you will have some discomfort in removing them unless you shave the area well first. If the area of your problem involves the scrotum for example, you might have some difficulty getting it denuded of the hair, and therefore might want to take a different approach.

On the good side, the patches are convenient in that you are not getting a strong cream on your fingers in application. The ingredient is only on one side of the peel-and-stick patch. With care in handling, you are unlikely to get any on you fingers. With the creams it would be advisable to wash your hands thoroughly so that you would not accidentally rub any in your eye. These patches can be cut to specific size. I use small patches on the wrists, triple the size for the shoulder and hip. I am well satisfied with the analgesic results. Even at this level of mildness, you will likely experience some warming of the surface that they are applied to, which could easily be exacerbated in a hot shower.