If you fish a lot of didymo-infested water, then you can probably surmise why my boots, waders, and net are in a freezer. Since freezing will kill didymo, I typically use this method of disinfecting my equipment as opposed to soaking it in the usual bleach and chemical solutions. Most guidelines recommend that you freeze your gear for at least 6 to 8 hours, but I usually leave my stuff in there for at least 24 hours. Or until my wife discovers it. Whichever comes first.
(Don't know what didymo is? You're kidding, right? No? Ok, then read this )
The link above refers only to New Zealand waters, but we have plenty of this stuff here in the US. The South Holston for example. Which I fished not long ago. Which is why my gear is in the freezer.