If you want to do bis, tris, delts or calves... go for it... but chest? trust me, unless it's 100% even vertically and horizontally and on both pecs, it won't look good at all. yes, you will get size but at a price. one of the top amatuers that was competing in the arabian championship 2 years ago was marked down to DEAD LAST! because of apparent synthol use in his pecs. my friend (the guy who won that weight class) knew him pretty well and he told him that he stopped the pumpn'pose 8 month prior to the contest but his chest got permenantly deformed. lumpy, and the cavity between the pecs was non existent... it just looked like one big slab of muscle with two nipples on it. if you don't know what you're doing 100000% with your pecs and SEOs, don't fucking do it. If someone who has done it 10's of times and taught people how to do it was personally with you to help you and show you exactly where and how much to shoot (someone with very thick pecs but not up to par would need a lot more oil than someone with half the thickness, for example) don't do it.
With all respect to Big A, the pics in the injection location site just have an anamtion and arrow... it just tells you generally where to inject.
synthol has done wonders to a lot of people in the arm and calf area... but pecs? traps? back? quads? those areas are too big and need someone with experience to show you IN PERSON!
that's just my opinion.