ACROSS
6. <multipurpose unit> STEM CELL = ST EMCE_ LL
8. RAY outside EPL = REPLAY <second match>
10. SS OO inside CONTRABAN_ = CONTRABASSOON <rare and expensive instrument>
11. WOO + F = WOOF <call from boxer?>
12. <pirate> FREEBOOTER = FOOTER outside ←BEER←
14. <pretty> PULCHRITUDINOUS = (LURID CUSHION PUT)*
16. NA ←RUT← ALGA'S = NATURAL GAS <fuel>
17. <test> EXAM = ←MAX E←
19. CHEERS outside (_E _S _E + ←GRUB←) = CHEESEBURGERS <fast food>
21. STRODE* = DORSET <part of the West Country>
22. <potentially shocking> ELECTRIC = ELECT RI C_

DOWN
1. SCOUT* outside C = STUCCO <plaster>
2. (RAF I_ R_) inside TAMER* = TERRRA FIRMA <land>
3. L inside FIBBER TIG I_ B_ BET = FLIBEERTIGIBBET <someone irresponsible>
4. <advantages> PROS = "PROSE"
5. MAINE outside M + N U = MAIN MENU <options at start-up>
7. <they fabricate> MANUFACTURERS = (MAN U) F[_]ACTURE[R]S
9. PRONOUN CEMENT = PRONOUNCEMENT <declaration>
13. <one riding waves> BODY-SURFER = _Y inside (FREUD BROS)*
15. <get ready to sail> UP-ANCHOR = (PAN C) inside HOUR*
18. <descend by rope> ABSEIL = AB "SAIL"
20. <appease> SATE = ←ETAS←