If the tripe you get is still grey/blackish in color, soak the tripe in hot boiling water (make sure the water is rolling boil) for 10 minutes. Then carefully remove it from the hot water and when it's cool enough for your hand to handle, use a very sharp knife to scrape off the grey/blackish layer off. It's quite a tedious job I have to warn you. If it gets a bit harder to remove, you may need to resoak it in hot water again to loosen up the grey layer and continue scraping them off
The tripes sold here is already white in color, meaning they have been bleached to remove that grey/blackish color.
Rub the tripe with rock salt at the front
and the back of the tripe too
Use a sharp knife to scrape the tripe all over (front and back) to get rid of any impurities. The back of the tripe is the membrane that you want to scrape off because they turn tough when you cook them. You may need a little brush (like toothbrush) to brush through the honeycomb tripe (especially if you have the yellow tripe). You may need a little brush (like a toothbrush) to brush through the honeycomb tripe (especially if you have the yellow tripe)
Rinse generously with white vinegar
Bring a large pot of water to a boil. Add about 1 tsp of salt. Add the tripe and boil it for 15 minutes. Discard the water after that
The honeycomb tripe is now ready to be used in any recipe that calls for it
Cut the tripe into desired shape or size if you like. They can be kept frozen in the freezer for up to 3 months