BLUE TONGUE SKINKS

A few days ago I noticed my Merauke was starting to get very dull and gray and I assumed it was just going into shed. He hid under his log in the dirt for about 2 days; I just assumed he was getting ready to shed. Yesterday I took it out of its tank to look at it and he suddenly wasn't gray anymore and looked like he shed, but there was absolutely no sign of any skin anywhere in his tank. Then I noticed tiny little black bugs on my skink, I'm really worried because this is my first time taking care of a bts (It's not even mine I've been watching it for someone else), and I'm not sure what to do. When I get home today I'll probably fully clean its tank out and wipe it down (Maybe with vinegar/water mixture, Ive used it for other reptiles and animals? It should be fine right?) Can anyone tell me what mites look like and how to get rid of them? Preferably something affordable as its not my skink and Im not being paid to take care of him (as far as I know). I don't have any pictures of the bugs but I'm pretty sure they are reptile mites, please help!

Typically, the harmless types of mites will show little interest in your skink and will be found in the substrate and on the food. When you find the mites actually on your reptile, chances are they are reptile mites. If this so happens to be the case, as it seems you've indicated, remove and trash all of the substrate in the enclosure. Disinfect the entire enclosure with diluted vinegar and then dish soap. Any of the hides that can be placed in the oven can be baked at 250 for an hour to kill any mites or eggs. Anything that can't be treated with heat can be left outside overnight to freeze, assuming temperatures will drop under 40 degrees. There are topical treatments that can be used, however I would let the owner determine if that's something he/she is willing to do. Line the enclosure with paper towels and soak the skink in warm water and a drop of dish soap to try and rid it of any mites. Note that mites will sometimes embed themselves under the scales, in the ears, or in the armpits (don't get any water in the ear holes). Keep all of the existing hides removed from the enclosure and use disposable items like old T shirts as hides. Remove these items everyday to wash them, change out paper towels, and soak the skink daily. You should be able to monitor the mite infestation this way until it is eradicated. If you can manage to squish a few of the mites on a paper towel, reptile mites will typically leave a pooled blood stain since they feed primarily on blood, while the others consume decaying matter such as mold, shedded skin, and your skink's uneaten food.

Ditto above advice, and just to add, if you have any other reptiles keep the skink in another room as far from them as possible, as female mites go rogue and travel some surprising distances to lay their eggs at times. Warm damp areas are a favorite, as these mites are for the most part tropical.