Even if there's a slight chance, you won't find out unless you try. And even if it doesn't help with the scoliosis, UT will likely maintain your child's health and keep other related problems at bay.
How to do it? Start with giving the first morning midstream urine and proceed from there. If it causes unpleasant symptoms (signs of healing crises), reduce the quantity, if not, increase accordingly.
Learning more about yoga may be a good idea. Yoga deals with bone structure, etc.