Dismantling Garrisons and Fortifications

Found the 2009 post describing how to do it. Further questions: how long does it take to do so? I keep setting to 0 in my main (Golden Rainbow) - but it never shows up in operational log. Should it? Perhaps my supply units are overburdened? I've noticed that repeated attempts to restock my bomber wings have gone unheeded. (those couple missing planes from last war.)

Made the mistake of building fortifications in my main - to little purpose. Can't deactivate them. Is there anyway to destroy them? I'd like to get those soldiers back into productive positions, like manufacturing - since main country is currently protected from attack.

Many thanks for your time and consideration,
Marshal Ney, Grand Duchy of Marshall, and the Municipality of Elchingen.

Dismantling units/garrisons will happen in an hour or two. You dismantle by showing them on your war menu and pressing dismantle, dont know what you mean by setting to '0'.
There is also a link there to destroy weapons/ammo which is what you will need to get rid of the unwanted forts.

If your not upgrading wings, dismantle and rebuild them (instantaneous) and they will be back full. Unless I'm in war I dont generally keep offensive wings like bombers active because of the cost, but I make sure to buy top Q weapons/ammo for them so when I do need to build them they will have some decent fighting quality.
Else you could leave them active and upgrade them...you do the math.

On the war page,

During war, Garrisons are deployed and dismantled by Supply Units.
Make sure you have enough Supply Units if you want to prepare for war.

I'm setting the sliders to 0 on the blueprints, and choosing undefended. Think it was a matter of overburdening the supply units. Just can't seem to queue it. They are slowly coming down now.

I know about the air wings - mine are up because my slave country comes out of war protection soon. While I may only be on GR, I think it's a good habit to get into - for when I do come up and play with the big boys. I've got a couple of neighbors that could prove troublesome. Especially if I took their piggybank away from them.

Weapon and Ammo Q's are now being sought. Same for highest quality weapon systems. (Appreciate the tip!)

Well, you also have the option to set each target to undefended which would remove all garrisons. I guess your technique should work, I've just never heard of it being done that way. Seems a little slow and complicated to me. But if it works for you, fine.