howdy - and welcome
the 'long cotton' that comes from Sally's is actually rayon (called cellucotton - 100% rayon fiber)... you can actually get the pads from Sephora - called Koh Gen Do - about $14 for a pack of 60 pads (or online from Sephora, or
through amazon also)
personally, I like Cotton Bacon for my drippers, though I am in the process of testing rayon also, heard a lot of good feedback about it... but I use Koh Gen Do pads for all my rebuildable
tanks
hope this helps!