Throttle body cleaning, how do I clean it without damaging it?

Hello again, and thanks for the help as I'm disabled and not working with major medical issues. I need a little more info before proceeding. So, here are my questions:

1. I don't plan on taking the throttle body off. I'm going to clean it in place by removing snorkel hose out of the way.
2. Why does the battery need to be disconnected?
3. I need to make sure I don't damage the mechanism when manually opening the butterfly. When I move it all the way open will it stay there. Then after cleaning it should I put it back in the closed position before reconnecting the battery? I was told that there are gears that can get damaged if you force it open or get something out of calibration. If you open this electronic type, will you feel resistance of the gear mechanism and need to go really slow with it.
Thanks, Robert

You have been very helpful, so thanks. One more question. My car has very slight rough idle so I'm going to clean throttle body first and see what happens. However, I have the original spark plugs on car with 72,000k miles. Looking at my manual maintenance schedule I believe it shows to change on 2006 Corolla 120,000. I don't want to do it any sooner than necessary so what do you recommend? Thanks

Thanks for the info but could you give me your recommended plug change mileage for the 2006 Toyota Corolla? Also, I don't think if I take them out and inspect them you could put them back in as the crush washer at the base has already been squashed.

Unable to read. Was blurry.

Never mind. Sorry it was my error. Could you tell me where to tighten the drive shaft bolt they are talking about? Picture please.

Looking at the chart you sent me on 2006 Corolla spark plug change I believe it shows 120,000 miles. Is that correct? Also, I'm getting ready to clean throttle body with that cleaner. I was told just to spray a rag and wipe it but not to spray it in the opening. I remember having a 1997 Camry that gave me idle problems and there was a small slot that a Toyota guy told me needed to be sprayed. Does his 2006 also have that idle slot that needs spraying also? Thanks for the help. You guys are the best.

Thanks.
This has helped a little after cleaning and now I also purchased a can of mass airflow sensor spray so I need to know if I should take out the two screws that secure it and lift it out without disconnecting electrical cable or disconnect the cable and then take it out and spray it. Does battery need to be disconnected again or not? Thanks

Thanks Sean. You guys have been wonderful and provide a great service.