cafiene as a slug & snail killer

[remo]

Have been reading online about cafiene sprays & drenches to kill/drive out slugs & snails from potting media. Do any of you have any experience using cafiene?
Have any of you made a tea to spray? One research finding suggested .5% cafiene spray would work over several days and applications but a 1-2% concentration drove them right out or outright killed them on contact. I wonder if it is really safe to the tender new roots. Any thoughts or experiences?
Thanks,
Remo