You can boil them 20 minutes in water to sterilize them, but if you want them really clean I would wash in soap and water being solid glass hot water, rinse well then put in bleach and soak 24 hours (covered) room temp water, rinse thoroughly, all bacteria, fungi everything dead. To ensure no bleach left do the boil and cool they can be reused in a new tank or are sanitaryq enough to put in your mouth.
I have many beautifil polished rocks, and natural crystals in my tank, they all turn brackish green in a year so I clean, disinfect and boil them. My ceramic things are also cleaned the same but I also scrub with a toothbrush to help the small racks. Never had cros contamination or soap residue issues, I take one day each procedure to temper the items so they are not forced to heat or cool. Always need at least three to four inches water covering them especially the bleaching then the boil. Don’t slam cold water in after the boil they will crack or explode. I let them stand in the water till nest day and rinse then dry them, store in baggie, seal after several days once all moistures out,
I’ve heard of baking things but I can’t have my oven out of commission several days.
Never bleach the tank as it doesnt come out of the calming, it’s semi absorbent with the only exception methalyne blue stain. Choice between tossing the tank and using dilute bleach try the Duluth first.
Out first 75 gallon hex got stained, my x used the whole bottle medication to treat because he panicked, killed the fish and dyed everything in the tank blue. The rock stayed blue forever because it’s semi Peru’s but the rest I bleached and was fine. The tank stayed open several months till no trade of the smell remained.