walnut shell is going to be hard for him to pass. i dont see how you have diagnosed his impaction down to 7 hours, sometimes beardies will skip a day in thier poop schedule. you only need to start freaking after about 4 days + but after 2 you should start taking precautions. I had a scare a few months back with impaction, pretty mild one. as long as his legs arent like immobile than its not super severe(at least thats one sign of a bad case). put him in a nice warm
bath nothing hotter than what you would
bathe a child in. i wouldnt rub his underbelly because walnut shells are quite hard and you may cause it to cut his intestines. let him soak for 30min and repeat around every 4-6 hours. try to get some water in him if you can with an eye dropper. and just wait it out. if its been 4+ days i would really seriously think about taking him to the vet because at that point id consider it a serious impaction and if not properly taken care of
you will lose your beardie.. as suggested by alot of people on this site thinking of getting dragons, one of the first things you do is set asidge money for emergencies like this. make sure his basking temp is 100-110 and hes getting the propper amount of UVB. do not feed him live food while dealing with this stick with just simple greens. when it comes to impaction you do not need a reptile specialist, local vets can perform enemas just call ahead to double check.