There is another approach to handling bouncy switches which we used to read reed switchs with very little power which is to use a astable with a very low mark/space ratio something like 1/1000 and a period of about 0.1 seconds and monitor the resultingoutputs .We used it because in low power systems switches can become polarised due to oxide on the contact surfaces,using the pulse system you can put high current through the switch,break down the oxide and still keep the power consumption low.