Me too, I've done it...flown with someone that has done it. All will be well though as you'll quickly realise and after an expletive you'll turn off the
real anti ice. Unless you're flying with autopilot B engaged then there is the added excitment when it disengages after loss of B hydraulic pressure
BTW, the 737 does do flap 1 departures for normal operations if performance requires and it will not sound the config horn. Unless a particular airline askes for it to be designed that way with I higly doubt.