Do these make a diffrence?

http://cgi.ebay.com/ebaymotors/DEVILBISS-DESICCANT-SNAKE-IN-LINE-AIR-DRYER-WATER-TRAP_W0QQcmdZViewItemQQcategoryZ43987QQitemZ4641439286QQrdZ1

Would using one make a diffrence. I already have an oil/water seperator. I just want to make sure it works before I buy some of them.

it should help a little but if moisture is making it that far in your line you might wanna back track to where the problem is. get some new traps or run a new air system

I guess it would help some. Im not sure of exactly what the name is but I use a "toilet paper" filter. They call it that because the filter inside looks like a roll of toulet paper. I run an oil/water seperator, the "tp" deal, and the use the disposable inline filters before the gun.