I always take a dremel to the hole and soften it up; any broken edges, too. Worked wonders for my breeding kribs before that apocalyptic failure. There's an attachment for clay and soft rock you can get for cheap at Home Depot if you have a dremel on hand, or they might just let you rent one out for a few bucks. My betta just sort of stared at the pots and never went in, funnily enough, even in her own hospice 5g...I think she was an idiot, though.
THE REAL advice here is too center-out the tank regarding decor and plants, creating breaks in lines of sight, and adding more mid-level hiding areas in addition to ground level rocks and caves and such. Floating and mid-level plants attached to decor and such go a VERY long way in this aspect. I also find that non-toxic pvc tubes make great floating respites when held in place by floating plants and driftwood, etc.. I'll take a pic of mine later once I wake the buggers up. My gourami practically lives in his tube, as it is easier for him to get food and air while not being bothered. Just my $.02
THE REAL advice here is too center-out the tank regarding decor and plants, creating breaks in lines of sight, and adding more mid-level hiding areas in addition to ground level rocks and caves and such. Floating and mid-level plants attached to decor and such go a VERY long way in this aspect. I also find that non-toxic pvc tubes make great floating respites when held in place by floating plants and driftwood, etc.. I'll take a pic of mine later once I wake the buggers up. My gourami practically lives in his tube, as it is easier for him to get food and air while not being bothered. Just my $.02