I used to use the knee in the chest... thirty years ago or so!! When you
know better, you do better!!
Some good suggestions as to leashing them up. I think what you really
need to do though is go back to basics, and firm up their sit/stays or
down/stays. Do they have a place they can go (such as their own beds?)
I would put them there, perhaps with a toy... a Kong makes a good
thing for them to work on, put some peanut butter in it.
Other than that, you need to put the dogs on IGNORE!!

Make
all the comings and goings of the household casual and no big deal.
When you get home, ignore them for 10 minutes or so until they settle
down, up to and including turning your back on them. Leaving the house,
same thing no "Bye sweeties mommy will be back in a little while" just
ignore them for some length of time before you leave.
They CAN learn this, never fear. Be very firm, dogs actually like a firm
leader, it gives them confidence.
I wouldn't seperate them or lock them up when people come over, that
works to a point but can also just exacerbate the problem. You need to
regain control over them, show them who alpha is and that is always
YOU.
Tell all your visitors what you are doing before they arrive. THEY have to
ignore the puppers for a while, too.
Good luck and let us know how it goes!!