Most plants come from hydroponic culture, not submersed grown.
So algae is not an issue. Many species of algae are airborn, so disinfecting them does little if the top of the tank has any openings.
Thus sterile technique is a poor method for algae control in general. That said, a dip in Alum works well, or lime, or dip in one for a bit, the followed by the other for a few minutes each, then rinse.
I pick and clean and the plants when I get them and typically soak in chlorinate tap for a day in the dark. BBA, Hair algae, etc are wiped and picked clean.
I think a good home is much better than trying to prevent the spores from entering the tank. You need something to germinate the spores, then it no longer matters if they are there or not, as long as the germination triggers are managed, there's no issue.
That will help whether you try and maintain sterile technique or not.