I'm with Charles....This has been discussed time and time again...we all differ on what we are willing to accept as 'safe enough' and we always will.
I say nothing is 100%...do you best at staying clean, but still have fun with it...otherwise, what's the point? Money, and setting your own schedule is not enough for me to do something in which I do not enjoy. So I AM going to have fun, damn it! Life is short, and you only live once.
Be somewhat selective, keep yourself clean, pay attention, use your senses, keep you condoms close at hand, and always pay attention to yourself and you instincts....if in doubt, don't do it.
One major thing I have changed at home since becoming a part of this is that I do not share drinks with my son anymore!
I'm no longer comfortable with doing that, and it doesn't matter what educated reasoning you may give me on how it is pointless, I still would not feel comfortable with it.