Old wives tail about tires, true or not?

[AnthonyG]

I have read online ( not always always the best source ) that a liberal application of antifreeze to old tires ( off the car allowing several days ) gives them new life by allowing the glycol to make the surface matrix structure pores allowing the rubber to absorb the lubricating property of the antifreeze rejuvenating the tires. Preventing the surface of the tires to propagate cracking.
Sounds like maybe just does the same thing as any surface dressing application?

Have also read online that five to seven years is the max safe age to use a tire? Seems like maybe the Mfgr's pushing that to get us to buy lots of new tires.

Opinions?