Greggs in Bellevue confirmed that shelf life thing on a tire that I bought 2yrs ago as a spare...When I put it on last week, the sidewall bead sortof bulges itself off the rim while you're inflating it (or while you ride it at full inflation). It's a large noticable bulge, so I suppose if you rode it anyway the tube would pop.
They sold me the 06 All-Condition that doesn't have good traction on turns and wet steel grates. Most of us know that wet turns and steel grates are slippery when wet. By 'bad traction', I mean even when slowing, the back tire skids out slightly and you have to comnpensate not to fall. Slowing, on those same stretches of road, with the older Turbos and All Conditions, there was no sliding.
Just the same, I'll try your soap idea.