Here is a novel method for cleaving methoxy groups from aromatic compounds, using methanesulfonic acid and a microwave oven. The reaction time is approximately one minute.
https://www.thevespiary.org/rhodium/Rhodium/pdf/ether.cleavage.msoh.mw.pdf (https://www.thevespiary.org/rhodium/Rhodium/pdf/ether.cleavage.msoh.mw.pdf)