oof. thats quite an infestation. Yes, I would try the soap solution.
1 spoonful of dish soap (natural dish soap if possible, try to avoid all the super scented stuff, its full of dyes and perfumes)
1 spoonful of vegetable oil
1 litre of water (mineral water if possible)
Mix it all in a spray bottle and generously apply. Take some tweezers and pick off everything you can first.
That mixture should be harmless to the plant itself.