Loose jack on concert; classical guitar strings on a bari

I first noticed a buzzing from the G string on my concert a few weeks back. I read the whole thread about buzzing and eliminated a lot of the possible causes. The buzzing was only noticeable when I was amplifying and really only when I played fairly loudly. Soon after that, I noticed that the jack is loose. It turns with little resistance and the whole assembly feels wobbly. Must be the source of the buzz

To fix this, I take it I need to turn the nut clockwise while holding onto whatever it threads into on the other side... in the interior. But there's no way my hand will fit in the soundhole much less deep enough to reach where the Jack is located. Do I need the help of someone with very small hands?

My second question is about strings. I had the same set on mine for a couple of years and they were starting to sound pretty dark. I'd also recently re-strung an acoustic guitar with "classical" strings and I didn't like the sound on that instrument. I live in Yangon, Myanmar, where there's not much in terms of ukulele supplies, so I took the DGBE classical guitar strings and put them on my Kala Baritone... sounds a lot nicer. 3 of the 4 strings are nylon. I'm not taking any risks here, right?

You might try taking a screwdriver or something similar (wrap the end with tape to cover the points) and putting that slightly inside the jack to hold it steady as you turn the nut from the outside.

Baritone strings are usually just re-packaged guitar strings.

I use the "Allparts Bullet" guitar jack tightener. It has a little plunger piece that snugs into the jack to keep it from rotating inside the uke, while the other portion fits over the nut so that you can turn it clockwise to get things nice and snug. Kind of a more "high-tech" version of the suggestion made by Jer! It runs about $12.00 on Amazon, Musician's Friend, Stew-Mac, etc.

A piece of wooden dowel or similar. There is usually a nut inside which may have slackened back. In this case you will need to bite the bullet. Insert an old string through the jack hole into the body. Drag it through the sound hole and secure it, wrap it around something longer than soundhole diameter. Wrap jack end of string around a pencil.
Remove outer nut, slide jack body along string out of sound hole turn loose nut up a few turns, secure with nail varnish or loctite.
Slide back towards jack hole. Waggle into place. Tighten outer nut.
It is fiddly but patience will 2in through.

Just as long as you use the proper tension for your Baritone you can't hurt it. Labels are mostly for ease of marketing. Realize a standard classical guitar has a 650mm string length vs the 510mm scale of a Baritone, so normal tension classical strings may feel a little floppy on such a short scale. If so, just size up to a heavy gauge/higher tension classical set.

Joko, I have Savarez classical guitar strings on my Ohana bari and am pleased with them. The tension seems fine to me, and no problems have arisen yet, though I haven’t had them on very long.

For classical guitar to baritone use the A string for the D, the D string for the G, unwound G string for the B and B string for the E.

I use thomastik-Infeld CF35 for D,CF30 for G and Savarez Red B,E.

!/4 inch wooden dowel should hold it to tighten. Taper the end a bit.