Hmm. Interesting idea... Might be a bit hazardous if you try and light it immediately after you put on the lid as the gas coming out may be a mix of acetylene and air between the LEL and UEL so could go bang!
Carbide generators rely on back pressure to regulate the flow of water so that excess pressure does not build up - this doesn't have one and acetylene under pressure explodes. That's why acetylene cylinders have the gas dissolved in acetone under only moderate pressure and plants handling acetylene have blowoff valves set to a few atmospheres pressure to avoid disaster.
Dave