Can you use sclerotheraphy for veins on the lips? I have a venous lake on my lip and am curious about what treatment works best.

Superficsl laser treatment is your answer.  Many doctor offices have a variety of lasers that should help. govdee a vein specialist, plastic surgeon or cosmetic dermatologist. 

For what you describe, laser treatment would almost certainly be a better choice. Not that sclerotherapy would not or could not work, but laser treatments, with the right laser, give excellent results, with no downtime, and very low risk of injury or complication. We have had great success in our office with these types of patients. There are several lasers that can treat this type of lesion, so you should be seen by an experienced vein specialist.