Don’t need an answer fast and this is a hypothetical thread and not a DIY thread.
I saw that certain Durex Condoms contain 5% of the local anesthetic, benzocaine. This is in a gel form. I don’t know biochemistry but I do know that from experience applying an anesthetic (especially gel) on an exposed form of skin like the head of penis, tongue, anus will work effectively as opposed to applying it on the finger, arm chin etc.
In other words, it seems like you would need a) stronger concentration of a small quantity of anesthetic or b) greater quantity of a minor concentration of anesthetic
Assuming our hypothetical individual could only induce numbness on their arm using a 5% concentration of a tiny amount bezocaine located in condoms, how many condoms would they need to induce numbness for a period of time?