You can give an armor/sword to a mob than kill it while having the raden charm on you, and get 2 back.

WHICH version you using and WHAT mob at?

That was already fixed in 2.8i, now mob holding item is not target of flower charm.
Information is missing. I can not fix it.

That's with AppleMilkTea2-1.7.10_2.8o.jar with vanilla mobs.

OK, on next update, the flower charms will lose the effect to increase all damageable item.