WordNet (r) 3.0 (2006):

unclogged
    adj 1: freed of obstructions; "an unclogged drain"

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "unclogged":
   bald, bare, clear, cleared, disclosed, disembarrassed, exposed,
   free, naked, open, unburdened, unclosed, uncovered, unembarrassed,
   unencumbered, unhampered, unhandicapped, unhidden, unhindered,
   unimpeded, unladen, unobstructed, unprevented, unrestricted,
   unstopped, untrammeled, wide-open