Next time dip your waxed sponge directly into a bowl of alumina Hydrate and then wax the lids dip in powder then wax etc.
As a long time potter the pro tricks are these that is unless the tops are glazed on inside
1st I use a large piece of bamboo about 2 to 2/12 inches round and 14 inches long to use as my tapping hammer-I have used the same one for 30 plus years
a wood handle works best if no bamboo is handy ( I grow all kinds here)
Tap the pot while holding the lid do not strike the thin top edge hit the top near the seat but the solid part of pot
This tapping takes time to learn how not to brake a pot but hit it hard enough to come loose-you tap while turing the part so you tap all around (the rubber is not the right tools as it dampens the blows)
Again hold by the lid tap aronf body near top-be ready for pot lid to separate and fall (so do it near table surface)
Do not heat with torch (you will thermo shock it.
Now if this fails we move to phase 2
This has always come thru for my porcelain pots-I have done more than you can imagine this way
I put them in my chest freezer for at least 4 hours or overnight.
I fill sink with hot warm water 2/3 full so when the cold pots comes out i can hold it BY the lid and put it under so lid is still dry(cold) and pot is under water almost to lid-they often pop apart-a few time this took a few tries (freezer again till cold-and another hot water dip_
The idea is the cold lid stays cols the pot expands and bingo its free
I have never broken one this way either Daves porcelain is tough.
Try this and let me know how it works out
Good luck it always works.