Yeah, that’s the problem. I suppose some sort of high pressure sprayer and fans could get it quite a ways in and then when she blows the shock wave would affect people a lot farther down than just the area of the explosion. Especially in such a confined space.
How about a little robot car dressed like Mel Brooks as a bellhop, playing a recording in Arabic, like: Mr. Hamas. Special delivery for Mr. Hamas.
But seriously, if there is a bunch of reinforcing concrete poured at points, they will sometimes need to deliberately emplace demolition charges, which will require that the tunnel be cleared of booby traps and enemy first.
They probably need a suite of tools for different tunnel situations.
Something for rapid clearing for infantry or intel to burst in quick to exploit intel.
A few things for deliberate/definitive clearing and destruction.
A few things for quick destruction with minimal troop exposure.
A few things for quick extensive damage when time is of the essence (e.g. hundred gallon per minute pumps on gas trucks, diverting nearby sewage, fuel tanks or water supply into tunnels).
Tailored air and artillery delivered munitions.
Ground penetrating radars, aerosol markers and sensors for digging activity to map and track tunneling.
Special protective/recovery gear for IDF personnel engaged in delivering flame, frag or explosive weapons into tunnels.
Man-portable machines, small robots or special MHE that can help quickly hauling a ton of munitions into a building, down the stairs or ladder, and a mile up the tunnel.
Well developed and well practiced Tactics, Techniques and Procedures.
Iran likes to dig, they must be persuaded. Being cornered in a hole can be a liability as well.