Why are you trying to sterilize the seeds, and how do you know they are infected? It's more important to have good clean sprouting medium, but it doesn't need to be sterile. I would be worried about killing the embryo with any treatment, unless you are performing embryo rescue culture, but that is a totally different thing from just planting seeds.
I just plant seeds directly in pure coconut coir with typically good results if the seeds are fresh. Dry seed can be harder to germinate, typically taking longer and with lower germ rates, but I treat them the same.
I typically start them in communal pots, maybe 20-50 seeds, and when they germinate I separate them out and up pot them individually.
