IANAMBBIHWITFAPI: I am not a microbiologist but I've worked in the food and pharma industries.

Botulin has a F0 time of 3 minutes, meaning that after 3 minutes at 121,1°C (250°F, ew) there is one in a bazillion chances that a spore may have survived. The toxins are easier to destroy, but if you don't destroy the spores, those will turn back into bacteria and produce more toxins, aside from potentially colonising YOU later.

Most industrial sterilisers have an in-pipe dwell time between 20 and 90 seconds, depending on how hot they get the product, given that F0 = 90 seconds @ 121°C is the same as F0 = 9 seconds @ 131,1°C, IIRC.

At least that's what I remember, I don't design these things, I just make them work.

You can't reach 121°C by boiling the cans on your stove top, because at 100°C water magically transforms into steam, the only way to prevent that is by adding pressure. Either you dive in the depths of the ocean, or you use a pressure system, like a pressure cooker... but with a standard cooker, how tf do you discern what's the temperature inside? You'd need at the very least a pressure gauge if you don't have a temperature probe (because since increasing pressure increases the boiling point, the current pressure gives you the current temperature).