I'm fairly new to IAL but I ordered some since my Thailand bettas grew up in IAL steeped water. You can use them daily for sure! I wouldn't use the item you were looking at... go ahead and buy the whole dried leaves. The first day I plopped some in, all my males made bubble nests under them! They float for the first couple days then sink when they become waterlogged... you can see the beneficial tannins turning the water darker as each day passes. Apparently they'll start disintegrating but removing them at that point is purely for aesthetic reasons.
I was trying to find the exact ones I bought on ebay, but looks like she sold out. I got grade A large IAL... I think you could get lower grades, but they might not last that long since the tannins will release faster from ripped edges... it's all up to you!
I'd highly encourage use of IAL! My bettas are very happy with it! And I swear it promotes healing... my two girls in quarantine took 1 day in super concentrated IAL water to return to normal... they're chilling in there for at least a week though..