When Fry, Leela and Bender are being tortured by the Slurm
Queen, Bender is put through a machine that will turn him into cans of Slurm. The machine punches one hole through him before he is saved by his friends. This hole is quite large and can be clearly seen on his side. When they are running from the Queen the hole disappears completely. However, later on after they escape the actual planet and they are partying on their ship, the hole reappears. It can be seen when Bender drinks some Slurm and it falls out of the hole and into Fry's mouth.
When Fry, Bender, and Leela flee the Slurm factory with Slurms McKenzie and his two babes, the babes' shoes disappear and reappear.
Slurms McKenzie didn't really need to stay and "party" to trap the worm queen in the corridor, since his radio did most (if not all) of the work. However, he made it clear that he wanted to stay. Apparently, after realizing that he couldn't escape the parties even on Earth, he didn't want to live anymore. Besides, the entire cave-in scene is humorously ridiculous on purpose (much like most of the series).
The Slurm Queen's description of honey coming from a bee's behind and milk coming from a cow's behind is not accurate. Honey is regurgitated through a bee's mouth, while milk comes from a cow's udder (though the Slurm Queen may have just been saying these things to make her own product sound more acceptable.)