How to numb scalp with 5% topical lidocaine for microneedling?

Hi all,

I'm trying to take up microneedling again, but the biggest issue with microneedling has always been adherence due to the raw discomfort it causes me. Like I can definitely get through a session, but I'm not kidding when I say I'm letting a few tears run as I do it. I'm on minoxidil, so I definitely know there will be benefit even If I'm doing only 1mm or less because of increased minox absorption.

I've purchased some Ebanel Numb520 5% Lidocaine spray and would love to use it to numb up my scalp prior to microneedling, but the advice for using this is confusing.. People are warning that leaving this on for too long could cause lidocaine poisoning, but at the same time, people also say it doesn't work if you wash it off. So do I have it on or off when I microneedle? I don't want to get lidocaine poisoning.

My plan is this:

• On the day I am going to microneedle, spray the Lidocaine on about 1hr before I shower.

• Shower and shampoo my hair and clean it as normal.

• Afterwards, dry hair as much as I can with a shirt or something so it doesn't get frizzy. (I have long hair)

• Start microneedling away?

Would that work fine?

EDIT: I've used a dermapen, dermaroller, and dermastamp. I think the best ones for me given my long hair would be a dermastamp and dermapen. Ideally dermapen if I can make it work since buying new dermastamps everytime seems pretty wasteful.