Some poeple are resistant to salvia or ket or dmt especially first time. it's better to dose normal and do it again one week later for exemple. than doing full gram of 20X which is alreadyan overdose. so even if it worked at that dose he would just have blacked out. And woke up not remembering anyting, maybe feeling a bit traumatized while not knowing what happened..
I suggest you read the "All about Salvia Dosing thread".
Smell like tea n,n spirit !
Toke the toke, and walk the walk !