are you trying to look for the meat or bait item?
burn some trees in the OW as a few underground shops have it but after burning some trees
Yes, that's what I was thinking. Found so many secret entrances but clearly missed some bushes somewhere. I'm determined to find it; thanks for the hint!

September 13, 2020, 12:16:50 am
Hilariously found Dungeon 6 and 8 first, and basically every other entrance. Then I finally find the secret blowout shop. I was sure I burned that tree before but I must've got sloppy with the hit detection each time.
All's good and I'm finally back on my way. Thanks again for the hint!
September 14, 2020, 11:38:02 pm
A:20 X:00 Y:0A S:FA P:nvUBdIZC $887E: A4 EB LDY $EB = #$72
A:20 X:00 Y:72 S:FA P:nvUBdIzC $8880: B9 7E 69 LDA $697E,Y @ $69F0 = #$53
A:53 X:00 Y:72 S:FA P:nvUBdIzC $8883: 48 PHA
A:53 X:00 Y:72 S:F9 P:nvUBdIzC $8884: 29 3F AND #$3F
A:13 X:00 Y:72 S:F9 P:nvUBdIzC $8886: 85 02 STA $02 = #$08
So it loads enemy $13 for Dungeon 4, Room 1 (entrance). Which is visually some type of single digdogger?
Went to ROM $18882 and replaced $53 -> $18 (no enemy?). Seems to work for me after exiting and re-entering dungeon.
ROM $18812 = Triforce, Dungeon 4. $13 -> $18 (no enemy?).