Really simple.
Most likely they'll bring a box with a shitload of chargers and wont care if you grab a handfull. Hotels lost and founds are full of tourist's stuff that they'll never comeback to get or have them shipped, its yours for the taken.
Have not seen this posted in here, probably because its really stupid and simple, but from now on, whenever youre walking by a hotel, go inside and grab your free whatever(: .