Try your garden hose (No water though!!!!) and do it in the shade (hoses go limp in the sun) - Try sucking it the wrong way round with your existing vac or another one and shake the sh** out of the whole hose while your are reverse sucking it ...
Squeeze the hose till you find the blockage and then pummel that point - stand on it if you have too!
If the blockage is really hard you need to be careful - whatever is in it may puncture the hose
Dont cut it - get or borrow some bigger pipe rubber or whatever that fits inside and goes round the fittings to push thru it ..
Tomo
December 2007