I'll back up Roland
Also, I agree that 3 hours queenless usually does the job - they get bummed out at two hours, and every bee knows the score at 3 hours!
My only other suggestion - and I post this way too often - is to use a Laidlaw queen introduction cage. Type "Laidlaw queen introduction cage" search words into the search box in Beesource and read some of my old posts, or go straight to the source and read Dr. Harry Hyde Laidlaw's book,
Contemporary Queen Rearing, available through Dadant and Sons, also from Dr. Larry Connors' Wicwas Press -
www.wicwas.com for the whole explanation.
Briefly, the Laidlaw queen introduction cage is a wooden rectangle 5" wide x 7" long x 7/8" high with #8 hardware cloth stapled over it and a sheet metal strip attached to the inside perimeter and extending down 3/8" below the bottom of the wood. Select a frame with nice, flat, empty cells, brush all the bees off of it (remove all Q.C.'s), go inside your tent and place the young, mated queen on the comb and trap her under the Laidlaw cage, pushing the sheet metal into the comb down to the wood. Place this piggybacked cage-frame combo into the middle of the hive to be re-queened.
The only queen rejection I get with these cages is damaged or inferior queens that are poor egg-layers, which the bees always know about before I do. 100% queen acceptance is quite common using Laidlaw cages properly. The Laidlaw cage is a push-in type cage that allows the mated queen to begin laying eggs, which brings up her queen substance production, especially pheromones, that practically guarantees her acceptance. The tell-tale sign is if the bees form a ball over the queen cage, they are still attacking her. If you see no "attack ball formation", but instead nurse bees trying to feed her through the hardware cloth, they have accepted her, and you may remove the Laidlaw cage. Incidentally, the cage has no candy holes - the beekeeper does the releasing, NOT the bees.
Laidlaw queen intro cages are by far the best way to introduce a mated queen, and the single best prevention against laying workers. If you do get laying workers, I recommend the following sequence: 1) build a few 10-frame boxes with vertical slots for 1/4" plywood hive partitions such that 4 sections of 2 frames each can be made up (or just make 2-frame nucs); 2) divide the LW hive up into 2-frame groups; 3) four days later, the frames with the eggs (in the spotty, multiple-egg-in-one-cell laying pattern) are the ones with the laying workers. You can either divide the two frames into "1-frame nucs" and wait 4 more days (and kill all the bees on only ONE frame), or just kill all the bees in the two "guilty" frames (for efficiency I use a vacuum cleaner then spray ant & wasp killer into it - the frames are still good to use); 4) re-queen the rest using a Laidlaw cage and a young, mated queen, or newspaper combine the other bees with other colonies, or even make nucs out of them...depending on your situation, colony strength, nectar / pollen flows, time of year, etc.
Either way, the laying workers ARE DEAD, you kill very few other bees, and save most of them. LW colonies tend to be very recalcitrant about accepting new queens, so make and use those Laidlaw cages! She almost HAS to start laying to get accepted by a recently-LW colony, and Dr. Laidlaw's queen cage design gives the best protection and plenty of comb in which to begin laying eggs. IMHO, this "Divide-and Destroy" method kicks *** over the shakeout method for laying workers. Works every time, and you're done in 4 to 8 days plus acceptance time (up to a couple weeks with LW's).