Norm made textures for capsule (but that's static asset).
Capsule Textures Adds textures for the capsule to the game. Use the presets in the properties of the capsule. You can also download an archive with a texture template for self-coloring the capsule. The textures for the capsule are located in...
hub.virtamate.com
I don't know about blender/unity or making custom assets....but as for built-in dildo, no.
You can't apply any textures...
i mean you can, but it's gonna blend all colors together with no diffuse details.
Export UV template doesn't work on dildo, none of loaded textures work correctly, it just blend all together (main, spec, gloss, bump, alpha).
At that point you are better of just changing color, also decal doesn't work.
Try loading simple red&blue image, you gonna get purple/pink dildo in return.