Can we not just roleplay this out? We already RP out lasting effects from injuries anyway.
I hate to trot out the 'easily abused' line, but this idea does seem ripe for it.
>harm self 50
>harm self 10
>harm self 20
A simple timer could fix this.
Now that's an idea - more broadly. You could use the timer for logging out (you are too excited) and not just on 'harm self' but any time you are in combat.
In other words, you must wait X minutes after being in combat (or initializing harm self) before you can do 'bandage self'.
Some of the most heart-pounding moments have been when my PC has taken loads of damage, and I have to find a spot away from the damage maker and hold my bandage hoping the damagemaker doesn't find me again -- if there were a delay to this, this would be even better.