Pick a profile at random, and message the following
"I though it was you, wow how long is it since we last saw each other - god what a night that was hey!"
Now at this point, they'll be panicking thinking, shit I cant remember who this is, but they won't want to look dicks by admitting they cant remember you, so they'll be ripe for plucking
The above is said purely in jest, and I do not endorse using such underhand behaviour - scout honour