Generally, the best lubrication for rollers is none whatsoever, unless specified by the product's written instructions. There's just no need for it. But, some Williams and MTH rollers just seem to love squealing unless they get oil. When it's absolutely necessary (and I loathe doing so) , I use a small squirt of CRC "Electrical Grade" plastic safe conductive lubricant, and carefully wipe off the excess. It comes in a bottle like WD-40 and is available at most home improvement retailers.
Once you do apply oil however, you've made a commitment to ongoing maintenance because pickup rollers will keep gumming up without constant attention. The high friction, electrical arcing and heat seem to rapidly create a sludgy glaze which can only be broken up with more oil applications every couple of weeks. It's a vicious cycle.
