Change waste water Tap for a bigger bore???

[CYCLOPATH]

Hi All, has anyone changed the tap for the waste water. Ours blocks a couple of times a year. I can unblock it as per previous posts, but i was wondering about changing the tap for one with a bigger bore,
Anyone tried this
Ours is a T5.1 SE. We spend months off site in it
Option 2 is easier. That is to fit a tap in the overflow pipe, so i can close it easily to use a plunger in the sink