How important is it to hook a hook in the hook slot? Can you hook it on the opposite side of the bait?

Not important at all. I usually rig it with the hook in the slot, but I've caught lots of fish without that slot too. The best "Senko" style worm (in my opinion) is of course Gary Yamamoto's, and those don't have slots at all. But on the Dinger, the slot is there, so I use it. 

Yes you can . I have experimented both ways.   My favorite way to get a higher hookup percentage is to skin hook it on the side.

It’s designed so you don’t have to tex pose it to make it weedless, as it lies flat somewhat in the body of the bait. 
 

Just another reason why I use them more than a Senko

 

 

 

 

Mike

2 hours ago, basser27 said:

How important is it to hook a hook in the hook slot? Can you hook it on the opposite side of the bait?

Not sure if serious...

As long as the bait is on the hook straight you can hook it from any side.  When they start getting really beat up I rig them tail first.

After decades of using senkos, I found out only a few years ago why the actions could vary so much when I would flip a senko to rerig.  There's actually a designated top and bottom to a Senko.  If you rig a senko upside down you get a different action vs right side up. 

Since Yum doesn't label the dinger on the top like GYCB, I could see the hook slot serving that purpose.  

Other than the action possibly being a little different, rigging outside the hook slot won't hurt or help IMO.

I dont  rig the hook so it lays in the slot because it wont stay in place. YMMV

I typically use 4" dingers instead of a ned rig on a vmc rugby since there's usually too much grass around to go with the exposed hook. In my case I've used the slot and the other side about equally and haven't noticed any difference in the amount of fish it caught.