This noun occurs only here and, according to Adler, in the Ambrosian Lexicon.
It should be derived from a verb *a)sxalida/zw (unattested). Hesychius has the participle a)sxalia/zontes, which he glosses in the same way as (in another entry) a)skwlia/zontes. For hopping on a wineskin, as at the Askolia (on the second day of the Athenian rural Dionysia festivals) see D. Whitehead, The Demes of Attica (Princeton 1986) 214-215).
Alternatively, it could be connected with sxali/zw, "suckle" (see sigma 1766), with an alpha privative.