As Ian G said you can thin both with water.
My wife is much the same. “How much is that lot?” She asked; Eyes £5, sanding sealer £15, cellulose thinners £10, paint £10, Liguitex varnish £15, glue £5, tips £4, thread £3, cane £2, balsa £6. About twenty quid I lied, as It dawned on me that the floats I had lust made had cost about £12 each not including my time. “How much each in the tackle shop? She asked. “Um, about three quid each” I confessed. But these one’s are for special needs,” Hmm, special needs.” I left it there, lol.