I would not use Tru-Flate on any speaker unless you don't care how it sounds as it ages and hardens.
In order to properly coat KLH surrounds, the butyl solution sold by RoyC and vintage-ar is the only stuff to use.
As for using anything on AR speaker surrounds, it is likely not necessary. I suggest checking out the Classic Speaker Pages about coating AR cloth surrounds.
If worried about the cost, find someone local that also needs sealer and split the cost. Or buy more AR speakers to justify the cost. This reminds me, I need to leave Roy feedback.
I understand we all have our own opinions but for 17.95 you get a brush,enough sealer dope for 2-4 woofers depending how many coats your woofers need,instructions and his experience of a product that's known to work as original...not expensive in my opinion.
This is a much debated topic. Well at least it was years ago. There was a ton of work done to make sure it was the correct formula, and the years have proven it to be effective and safe. The risk vs reward just isn't there.
The window regulator in the 2004 Corolla was acting up, so I pulled the door panel to investigate and discovered a good amount of Butyl rubber used as a sealant. Harvested a bit and mixed it with some Xylene to experiment on a pair of KLH 17 woofers. The cabinets were well sealed, but the unsealed woofers would spring back quickly after pushing them in about 1/2 inch. After a couple of very thin coats of the Butyl/Xylene mix the woofers returned to their position more slowly after pushing them in. Takes a count of "One One Thousand" in time for the woofers to spring back after treatment. It has been a couple of years now and they are working perfect.
I posted this under the KLH sealant thread sometime ago.
You can easily make your own sealant with the ingredients listed above using just enough Butyl in the mix to get the job done.