It works. Here is a churn I did for my dad July end.

Amex 25K Gold (instant approval, sent secure email, CSR made note to bump to 75K points)
Amex Hilton (instant approval)
Citi AA Business (deferred decision, eventually approved)
Citi Premier Thank you (deferred decision, denied for too many inquiries, thinking of sending recon letter but worried that may result in another pull)
Chase Sapphire (deferred, denied, called to reallocate, approved)
Chase SWA (deferred, denied, had Chase continental in feb, BA in march/april, sapphire above, and then this. When I called for the Sapphire recon, CSR said I could not get both so I took Sapphire. Thinking of calling in 10 days or so when dad will have had the Continental card for 6 months and ask if they can close the continenal card and open the SWA. Any issues?)
BOA - Alaska (deferred then denied for short credit history)
BOA - Virgin Atlantic (deferred then denied for short credit history)

For mom, I will do the same churn except that I will skip BOA since they don't like mom and dad's 1-2 year credit history. Once AMEX gold starts reporting, I think their scores might go higher. The VISA signatures are useless for improving credit scores.