
Rotten weekend.
Yes, the items should be safe for a salamander after boiling.
Gravel can be boiled or baked, too.
For equipment that cannot be treated with heat:
Bleach will kill most fish diseases. (Lots of rinsing, soak in double strength dechlor, rinse again until there is no smell of chlorine. Sunshine will also help it evaporate)
Rubbing alcohol will kill Mycobacteriosis. (Lots of rinsing, but I do know if something helps to deactivate it)
Hydrogen Peroxide (Lots of rinsing, expose to sunlight)
Potassium permanganate (Hydrogen peroxide helps to deactivate it, and lots of rinsing)
Salt: Scrub everything down with dry salt and a wet cloth soaked in strong salt water. (Salt is an abrasive, do not use dry on acrylic tanks) You can run all the equipment with strong salt water, too, such as twice a salty as ocean water.
What I would do:
Treatment #1: Scrub everything down with salt. This gets rid of any algae and biofilm on the glass or equipment so microorganisms are not trapped.
Treatment #2: Rubbing Alcohol. Dropsy and dropsy-like symptoms are very common with Mycobacteriosis. (Lots of rinsing)
Treatment #3: Bleach. Wipe it all down with straight bleach, then run everything with lots of bleach in the tank. Kills most of other fish diseases.
Treatment #4: LOTS of rinsing, followed by running everything with a double dose of dechlor.
Treatment #5: Dry exposure to the sun. Ultra violet in the sun can kill things, too. Several days, turning things over to expose all sides.
Follow the sterilizing with the Fishless Cycle. Takes about 3 weeks. This extra time without ANY fish will likely starve out most other possible problems. Most diseases and parasites cannot live for long without a host.
38 tanks, 2 ponds over 4000 liters of water to keep clean and fresh.
Happy fish keeping!