Basically you shouldn’t have problems just use low intensity at start. As for conductive gel you could use salted water or cotton with salted water.
Vaseline is a good insulator and would therefore be a very poor conductor. Given the general sensitivity of the area, however, this may be a good thing..
Honestly, I’d just stick to kegeling the old fashion way. Although sure to increase overall strength, assisted methods are dangerous and will do nothing to increase your mental control over the muscle (via establishing neural pathways). If you insist upon trying this, just start slow and be careful. Happy gaining