How to remove the glue left after removing peel/stick shelf liner?

have you tried Goo Gone?

WD oil works well

Spray with Goo Gone and let set a few minutes. Then wipe off with a gently abrasive kitchen sponge.

Goof off works great but test in an inconspicuous place first

Good concentrated orange oil is a great solvent and it is not toxic. My favorite is TKO and it's an amazing cleaner and deodorizer for about everything.

A soft rag (t-shirt) with a clear oil such as almond will usually do the trick. I add orange to give it more power in removing the glue. As soon as you have done a spot, buff it with another soft rag to remove any little clumps of the glue and the oils. Some surfaces do not like citrus oils, but are usually fine as long as you remove the oil as soon as it has done it's job.

Try WD40. You'll be amazed.

I used nail polish remover it worked really well just make sure you clean it off as it smells I used lemon and water gave it a fresh smell

Goo gone