grease  

Re: grease

I have seen several people recommending cleaning the shipping oil off the bearings and packing them with grease, yes. It's also been posted officially (?) here.

Note the number there is just the tube form factor, there are others (and other viscosities) from Super Lube, the 21030 isn't the only valid option. I got mine in a 14oz tub, the number was 41160. It's the same grease.

BTW, The Super Lube datasheet says it's recommended you clean the previous oil/grease off but they don't say it in a sense that it's mandatory. Also, pack the bearings less than you would with other grease.

Re: grease

I clean the oil off and pack them with Super Lube PTFE. You can also use a lithium based grease. Either way after you go you can use a light oil to maintain them afterwards. Should last the lifetime of the printer.
At my company we use similar bearings and accidentally did not pack some of the bearings with grease and they failed within months of use.
If you read any product speck sheets they will tell you to pack these types of bearings with grease.