Do you believe in Magic?

I''ll bite. As annotated below:

1. Removing all telephone books from the house.
I don't see this, unless the telephone books are blocking the speakers or air vents on the equipment. But, if you are using them for isolation under equipment, or to sit on so you are at proper listening height, keep them.

2. Removing all plants and flowers from the listening room.
Plants are good natural acoustic treatments and look nice too. I'd keep them, but you have to be careful not to over water them. Also, watch out for strange infestations of bugs and plant diseases.

3. Removing all empty beer, etc. bottles from the listening room.
Good idea. Probably more sanitary too. Since I don't drink, not much of an issue for me.

4. Removing unused speakers from the listening room.
Probably the most important suggestion, i think, because those cones move sympathetically. Unfortunately, I have a large home theatre system in the same room as my hi-fi (not connected to each other, electrically or through signal cables), but the extra speakers are there, and it would be a giant pita to move them for hi-fi listening. I do turn the amps on that control them, to 'charge them' so they are less compliant and the speaker cones less prone to sympathetic movement.

5. Removing all unused amps and other components and cables from the listening room.
Dunno what this would do - isn't that sorta the old Linn mantra? I have a bunch of equipment for the home theatre system that is rack mounted in an alcove adjacent to the hi-fi, not part of it and those racks aren't going anywhere (they are about 6 feet high and bolted to the floor). I am not looking forward to breaking them down when i move, which- hopefully, will be soon. New dedicated and far less cluttered room to follow in new location.

6. Removing all Sonex from the room.
Sonex is an acoustic treatment, right? I haven't heard that brand name or term in a while. Not sure where you are going with this, some treatment, if properly applied, is good, but I'm not sure about Sonex.
7. Removing speaker grills.
Could improve things if not acoustically transparent.

Dunno if this was intended to be a serious quiz, but I did try to give you straight answers.
So, what's your take, or is it a joke?

Mostly personal experiences here.

1. Removing all telephone books from the house.
In the corners of you room of some benefit. Other than that no effect.

2. Removing all plants and flowers from the listening room.
Small plants are okay, but a large rubber tree plant is a comb filter.

3. Removing all empty beer, etc. bottles from the listening room.
Nothing.
4. Removing unused speakers from the listening room.
Without shorting plugs remove them. Even with shorting plugs better get them out.

5. Removing all unused amps and other components and cables from the listening room.
No effect that I have heard unless piled around the speakers.

6. Removing all Sonex from the room.
Soft foam is death.

7. Removing speaker grills.
If you have them, experiment. Some speakers sound better without grills. Others sound no different.

In addition to Geoff's fine list, I would add the following assuming you were foolish enough to pay for them:

1. Clever clocks

2. Brilliant pebbles

3. Magic dots

Thanks.

Just my observations:
1. Remove all ear hair
2. Remove all clever clocks
3. Trim fingernails neatly (toenails don't seem to matter)
4. Tie all shoe laces tightly
5. Ensure all window and door jams are nailed closed
6. Remove all brilliant pebbles
7. Secure all plastic album covers
8. Polish all belt buckles
9. Clean all ceiling fans
10. Use spray, not roll on, deodorant
11. Remove all magic dots
12. Tighten all faceplates
13. Remove dandruff from shirts and sweaters
14. Vacuum all rugs
15. Use Armor All on every power cord
16. Serve unsalted nuts
17. Don't invite real nuts
18. Close cover before striking
19. Shut down security system
20. Tell the neighbors you know better

Hope that helps

By definition, # 17 on Audiofeil's list is impossible. That's what makes this interesting.....