Kiaser after 1943 a towed or vehicle mounted multi barreled Knebelwerfer was often used as a smoke projector on the battlefield it was also used as a fire suppression weapon,
As the war progressed "Recoiless Rifles" were used more often because they had a number of advantages over conventional artillery,
No heavy trail needed, no recoil machinery needed, it was usually multi-barrelled and was much lighter than an artillery piece which made it much easier to move and it did not need a trained gun crew and it was both cheaper and easier to produce,
The downside was that it was wildly inaccurate and took longer to reload.
The whole subject of "Recoiless Weapons from the "Bazooker to the Stalin organ" makes for interesting reading

shaun