If sterility is a concern, quit using soil or naturally derived media like coco. You can sterilize soil or peat or coco but it’s laborious.
Use perlite, rockwool, vermiculite, etc.
Mites are not a “death sentence”, they make products that actually eliminate them. Dozens of acaricides on the market. It’s much easier than you’d think, and you never need to throw out plants. inb4 “chemicals bad” types.
Mites can’t live 3 years with no host. However, during the warm season, they’re everywhere, so reinfestation is always a possibility. Don’t take in outside cuts, don’t bring in outside plants to the grow area.
Bleach kills everything.