I have it down pat, after trying all ways!
Sea sponge is crap, too soft, breaks up when you're trying to remove it.
RAMER baby sponge and diaphram. Boots and Superdrug have Ramer sponges. Very dense, good for soaking up, but very soft. Never had any itching or soreness.
This never fails me now, have done it 1000 times plus.
The diaphram ensures that the sponge doesn't get shoved in too far if if you have a big cock heaving away!
This is what I do -
Starting period, 3/4 of the baby Ramer sponge tucked into the dip of the diaphram. I add a little lube and fold it.
Mid period, 1/2 baby Ramer sponge tucked into the dip in the diaphram.
End of period, but worried about browny/red slime deep inside? I just use the diaphram then.
Red condoms are good too.
Ramer sponges are ?1-2.