I've been into wet and messy clothes forever it seems and I do want to try gunge but I don't know where to go.

Splatter Emporium just opened up in the US:

https://umd.net/forums/introducing-splatter-emporium-us-based

Some more thoughts:

https://umd.net/forums/thoughts-on-splatter-emporium

There's messysupplies.com in the UK, they ship internationally but it adds a fair bit to the price.

You can search "gunge powder" on Amazon, there's usually something available.

I believe a new US-based supplier started up the other month, sure I saw some posts here, but can't remember the details.

All gunge powder is basically the same, you mix it in a bucket with warm water, easiest done using an electric drill with a paint-mixer attachment.

As well as Messy Supplies you could also try Messy Pup Gunge - They sponsored an event recently and I can confirm their gunge to be good stuff!

Another option is to buy Carboxymethyl cellulose from a bulk supplier. This works out a lot cheaper but remember you'll need some powder paint (or whatever) to colour it.
I've used the one linked below which was good though took some effort with an electric hand whisk. I think I used around 120-150g per bucket but your mileage may vary.
Lastly there are a few bit you can find on eBay.

The more expensive stuff will mix easier (just a wooden spoon) but you'll get the same results taking your time with the cheaper stuff - Depends on your time vs budget I guess.

https://www.messysupplies.com/
https://www.messypup.co.uk/
https://amzn.eu/d/bX18KWF
https://www.ebay.co.uk/itm/253122516903?var=552206733244

It's an easy job but make sure you've got buckets, something to mix with (again an electric hand whisk is great for munch up any lumps) and a good supply of hot water.

Most come in discreet packaging though annoyingly no one seems to be offering Click & Collect or delivery to a parcel locker yet - something that would probably be a big win for some people.

Good luck - because when its mixed right it is absolutely amazing stuff! Nothing beats it for me.

I used to make my own but messypup was a ton of fun to use last time I used it

Hi! You can visit our website at www.SplatterEmporium.com

We are US based so shipping will be much more affordable. We also offer free shipping on orders over $40 for our US based customers. We have a variety of colors and offer a standard and thick gunge!

(Working on new products for the future too!)

If you have any questions feel free to let us know!

MessySupplies offer click and collect from their eBay storefront.

The last few times I ordered direct from their website, the package went direct to a pick-up counter (cheapest delivery). I think the more expensive delivery options might let you re-route the package using the DPD app?