You may want to try DermCaps which have the Vit E/omega fatty acids, etc. I don't know the formulation of the Linatone Shed so you should compare it.
Vetalog is a hefty steroid and probably not something I would do very often.
I did alittle research into "swimmers itch" and causes for humans and possibly animals with the larval infections of the skin...
I guess my approach for the summer would be two fold. I would take a good skin/follicle flushing shampoo from your vets office. I would take a gallon jug and the shampoo with you to the lake. After the swimming I would fill the jug and place a few good squirts of the shampoo into the jug and shake well. Dump and lather and let it sit for about 2-3 minutes then rinse...Next do the same thing with a oatmeal/moisturizing conditioner...jug/mix dump...and let it stay on. Try it and let me know. You can start benadryl 25-50 mg every 8-12 hours during your lake trips and see if that lowers anything...lastly. If the itching occurs...ask your vet for TEMARIL-P ...it has a lower dose of steroid mixed with an antihistamine. You can give it in smaller doses during your lake trips and not have to put your dog thru the side effects of steroid injections!!
Goodluck
Dr.V
Dr. D.A. Vamvakias
Veterinarian