I have been a life long fish keeper, and what I know about paddletail newts is that they can be highly agressive and preditory, so there is very little that can be housed with them. And creatures that might be able to hold their own againt the paddle tails would probably out compete the the newts for food items.
The best thing to use to wipe algae from the sides of a tank is "tule", the stuff bridal veils are made from, available from any fabic store or craft store for about a dollar a yard ( which means 36"x 45"). It will not scratch glass or even plastic. I have found nothing easier to use or that works better.
If you are talking about algae growth on ornaments.... I generally soak the item in a mild bleach solution for about 1/2 hour, about two cups to a bucket (ususally 5 gallons).. Then the algae simply rinses off. Be sure to rinse the item well (if you can still smell bleach, rinse again). And to be on the sale side, soak item for another 5-10 minutes with a decloration product.
DO NOT do this with wood, I would not trust that all the bleach could be rinsed off or out of wood. Instead to kill algae on wood, put the piece of wood on a foil lined cookie sheet in a low temperature oven (the lowest setting on you oven, 180 -250) for about an hour or so. This also works well to "clean" and make safe a piece of found wood. The low temperature over a long period of time will kill whatever the wood may harbor, without setting the wood itself on fire. Allow to cool, and give it a quick rinse, before using in a tank/terrarium.
Lastly, depending up what kind of algae... lots and lots of water changes will also help to eliminate it and keep future algae growth under control.
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