Matt, I use regular 3 in 1 oil and have had no problems. I have heard that others have used sewing machine oil. I'm not sure whether air tool oil would work or not.

Don't hold me responsible if your Cobra bearings don't last on 3 in 1oil. 

The main problem is always so called brokerage fee and sometimes a mysterious item called "handling fee".
I am not even mentioning taxes that go of course on top of all these fees.

Example: I have purchased 10 LiPo envelopes (safe charging bags) using one of the US based warehouses. The price I paid was $26 USD but, when the bags arrived, I had to pay $38 CAD in Canadian fees and taxes.

These bags were manufactured in China so NAFTA import exclusion rules did not apply but you never know these days.

Canada Border Agency can qualify the product any way they want when, what is quite common these days, the product label says nothing about the country of origin and arguing with them is very time consuming and difficult.

Just get some 90w synthetic gear oil from a cycle shop or pack them with high temp grease. I think using light weight mineral oil you would have to service them too often.


MM

Matt,
The key to having things shipped to Canada is to never have it shipped by either UPS or Fed Ex.  If the place you order from won't ship by US Postal Service then don't order from them.  Not sure how far you are from the border, but if it isn't too far, have the items shipped to a parcel drop on the US side. Then hand carry it across and declare the amount.  I came through the border the other day with over $300 worth of batteries and was not charged anything. 
Alan Resinger