You don't need to sterilize. You only need to sanitize. One Step,
Iodophor, and StarSan are all commonly used sanitizers for this purpose.
StarSan tends to be preferred for a lot of people. Personally I like to use
Iodophor for this like bottles because Iodophor stains and is cheaper than
the others. You can't stain a bottle and since it's cheaper that's why I
use it for things like that. For things that are porous and could stain, or
for keeping a spray bottle of sanitizer on hand to spray tools or other
things I like to use Star San. It is stable as a sanitizer in solution in a
spray bottle for a longer period than Iodophor. I don't know much about One
Step but the one time I used it I personally didn't care for it.

True sterilizing takes heat and pressure. I know folks that maintain
cultures of yeast that sterilize their lab equipment for maintaining the
yeast cultures but for everything else they only sanitize. They sterilize
by using a pressure cooker for 20 minutes.

Regards,
Scott