i dont think you need Synthol to get arms that big, if thats what you guys mean by SEO,? SEO to me means Search Engine Optimization lol, so maybe im not getting what you guys mean by seo but i know guys with arms that big that never used Synthol, you can inject any steroid directly to any muscle and get the same effects for the most part, and im not talking about site specific growth from site injections like u might be thinking, im talking about site injections actually stretching the muscle fascia much like synthol does, and this will help with size tremendously! Thats why bodybuilders generally have huge asses even though they might have skinny legs and not workout legs, injecting oil into the muscle repeatedly will stretch the Muscle in much the same way!
Anyhow i dont know if he is using synthol or not, but i dont automatically think that someone is when they have 22 or 23 inch arms, as its quite possible without using synthol