I have a map and as one of the key values, it holds another map.  When I pass this via an invokeUrl, it passes:

{"normalField1":3,"normalField2":"Blah Blah Blah","normalField3":69,"subMap":"{\"subMapField1\":\"value\",\"subMapField2\":null}","normalField3":"More nonsense"}

The third party I am passing the data to does not like the backslashes within the subMap.  I can't do a replaceAll on \ because they may be present within fields - unlikely, but possible.  How else can I remove them?