Joh what I did was use a long qtip (it's like 15-20 cm long but also thick) to kind of poke from the side. Mind you this was when the belt was worn during the vacations so it wasn't fully clinging to my body, it had a bit of a space between. Poking the tip at a awkward angle doesn't feel that good for me personally but I was still pleasure.
The belt was fitted properly (obviously) and the side piece (like the covering at the edge of the metal so it doesnt chafe on the body) was kind of replaced with a less squishy one. More firm.