Removing multiple ground slimes at once

[Neerovra]

I thought the scarlet hoe could till a 5x5 area or remove ground cover ( slime, wood floors, etc. ) in a 5x5 area. It now seems to till in a 5x5, but remove ground cover in one spot ( despite the 5x5 overlay graphic).
I need the fastest way to remove the ground slime from the slime loop ( after killing the slime bug boss, of course)

I have some mods running, so that may be related to my problems.

[umop-apisdn]

Remove your mods.

That should be the first step in any troubleshooting. Coming here to complain that something doesn't work looks stupid when it doesn't work because you're running mods.