In Costa Rica, and perhaps other Central American countries, it stands for fake hippies - those that dress like hippies and try to look like hippies, selling cheap handicrafts and deficiently juggling on the street (save a few exceptions), but are quick to start trouble - many times ending up in violence (information came from various sources).
Chancletudos are well known to be thieves and troublemakers.
Chancletudas are well known to be very cheap prostitutes posing as hippies.
If you happen to travel to Central America, be wary of these people. Some are ok, but most are very shady.
..just a word of advise directed to travellers.
Mae, ese chancletudo no se ha bañanado en un mes, parece.
(Man, this chancletudo apparently hasen't showered in a month.)