This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
擌 combines 扌 (hand) with 筴, but the exact historical development is uncertain. It may have originally related to a hand-held bamboo tool or rod.
The hand radical 扌 beside 筴 (bamboo strips) suggests a tool held in the hand, perhaps a bamboo rod or pole.
For サク, imagine a hand gripping a bamboo pole and giving it a sharp 'sack' sound as it hits the ground: sack -> サク.