If the server is concerned about people using them to get into others bases why not use Grief prevention and disable the right click of pearls when your within a certain distance of someone else claim... unless your trusted.
Towny already has this feature build in
Code: Select all
############################################################
# +------------------------------------------------------+ #
# | block/item/mob protection | #
# +------------------------------------------------------+ #
############################################################
protection:
# Items that can be blocked within towns via town/plot flags
# 259 - flint and steel
# 325 - bucket
# 326 - water bucket
# 327 - lava bucket
# 351 - bone/bonemeal
# 359 - shears
# 368 - ender pearl
# 374 - glass bottle
# 385 - fire charge
item_use_ids: 259,325,326,327,328,342,351,359,368,374,385
For me enderpearls are a key item for getting in and out of tight situations... as a good way to travel in the nether.