I recommend not singing or, if you must, just lip-sync. And, finding parodies to lip sync to will help to a degree. As long as you can throw off the Filthful and Disgraceful Slavebugger's damnation working, it will have less power. Granted, not as good as not being there at all. But, it is better than not trying to vibrate the words in the song. And, given how dismal those songs sound, it isn't hurting anyone.
While you are at it, I recommend getting rid of whatever new Kingdumb maladies you chance to have. Cassettes can be erased--I triple erased mine with a bulk eraser, then recorded whatever music I felt like on top of it (triple erasing with a bulk eraser prevents any subliminal vibrations from surviving--each trip through the eraser nurfs it by 60-80 dB, and a triple run through the eraser plus being erased just before recording nurfs it by more than 120 dB. Most audio equipment cannot reliably reproduce things below -90 dB, so you have 30 dB of safety margin to play with.) With vinyl LPs and CDs, you are out of luck since they cannot be erased, but you can ruin them. Mini discs can be erased--a single erasing will do fine, since either the file will play or it will not (and, if you have another file on top of it, the original file is lost.) MP3 files, likewise, can be deleted.
Obviously, the less you are exposed to this smut, the better. Get rid of your Kingdumb maladies--if you must have something to appease the hounders, I recommend dummy labeling them. This means placing CD-R discs recorded with real music on discs to be stored in the boxes meant for Kingdumb maladies. This means having MP3 files of your favorite songs, but editing the titles so any snooping hounder is going to think they are Kingdumb maladies. If you must go to boasting sessions, try drowning out the Kingdumb maladies. While you might not be able to physically drown them out (as many of us used to do with headphones at work when Christmas music was going), you can try focusing on your favorite song(s) during the singing. Do not sing the Kingdumb malady--you may have your book open to the page but do not try following along. You might also try doing a simple void meditation during the song and prayer. Or, try and stay focused on a single mantra. Suryaye is a fine mantra to focus on mentally during the prayer and song.
During the talks, however, drifting off to sleep is a good way to have them embedded on your subconscious. You might not be able to recall what they were saying, but it is on your soul. You are in a trance while they are putting joke-hova's communist government ahead of material things, you have your mind programmed to poverty and your soul repels wealth. If you must go at all, simply practice some type of meditation. You will not be able to do anything that audibly vibrates anything. But, you can focus on feeling energy, working on chakras, or whatever you see fit. You can also meditate on the fact that Saturn is headed for Sagittarius, and use the time to prepare for the coming financial crisis instead of donating to the Worldwide Damnation Fund. Even void meditation, though I recommend that for shorter periods since it is too easy to drift off into a trance after 10 minutes or more, and then absorb the smut.
Those who are free to do so, you can blow it off and not go at all.