At Walmart all I have been able to find is the 6 oz. bottles from Humco.
This can be found in the skin care section. It is only labelad as glycerin 99.5% pure USP grade, not vegaetable glycerine. I have read where some contend that it has made them feel sick. I have been using it to blend and mix with for nearly a year now and have never had any problems as others claim.
For vegetable glycerin, Now foods and Wilton are popular labels. They are usually found in the crafts or cake/baking goods areas in grocery stores or bakeries. Online, Lorannoils.com is good source for such items.
Here is a link to the Humco brand sold at Walmarts.
Walmart Humco Humco: Skin Protectant Glycerin Usp, 6 oz : Questions, Answers, How To, FAQs, Tips, Advice, Answers, Buying Guide