Could liquid Lino be applied inside loudspeaker enclosures for low, mid frequency absorption?

At your risk.


Linoleum had been used in India radio for low frequency absorption in studios, see Acoustics for radio and television studios - Gilford - BBC - IEEE monograph


Linoleum had also been used as kitchen floor for many reasons including avoiding reduced breakage of dropped china.
See Wikipedia
https://en.m.wikipedia.org/wiki/Linoleum