You should be able to find equivalents of the materials I use for a "bath" method of placing all parts in a large, clear plastic bin and covering completely with liquid solution.

Find "20 volume clear developer". It's for bleaching hair and you can find it in beauty supply stores. I usually purchase a gallon or two and mix it maybe 1:8 or 1:10 with hot water. I also use about 1/4 cup (60ml?) of any brand "Oxy" oxygenated cleaning powder in with the bath. Dissolve the cleaner with a gallon of hot water before adding. Be sure to move your parts around every 15 minutes or so and check that none are poking above the water line. With strong sunlight, they should be done in an hour or two.