Yellow coriander wrasse is a great option but is reef safe questionable when it gets older, and if you have a bit of a bigger tank and a deepish sand bed melanarus (not sure on spelling) is a great fish and a beautiful wrasse as well.
A 29g tank is NOT suitable for any Halichoeres wrasse.
Unfortunately, the only wrasse that is and fits the pest control bill, are some of the Pseudocheilinus wrasses (ie - sixline). You might consider a pink-streaked wrasse; a smaller member of the Pseudocheilinus genus but much more passive than the others.