10% is pretty low , just provide plenty of juicy bugs and nice fresh greens and veg , and in this case , perhaps place a water dish in the viv so beardie can drink if
thirsty (some do) , and the surface evapouration from this will help boost the humidity.
Give the beardies a couple of drinks per day as well and they'll be fine....they are evolved for arid tropical climates.
In summer here (coastal subtropical NSW) I rarely see relative humidities inside the house under 60%(even with the big Fujitsu split (refrigerative) aircon running on 24/7) . Lowest I've seen is 30% when the "The Doctor" (NW or W winds) is blowing gale force hot dry winds directly from the interior of Australia - as happens every now and then in summer, usually the sea breeze over powers this not always.