Extreme long duration 555 timer without electrolytic capacitors [130257-I]

Ever heard of 1GΩ resistors? The 555 timer here has a duration time of about 270s; by using a high resistance value of 1GΩ, no electrolytic capacitors are required. The 1GΩ resistor RGP0207CHK1G0 is available at Mouser for about €0,50. See for the circuit here: http://www.avdweb.nl/composites/vacuum-pump-timer.html