Hi I use swish some years and think necessary add to swish some 
features like 
limit search result by some property name with unique value.

For example:
page 1 have property param="test" and content "someword"
page 2 have property param="test2" and content "someword"
page 3 have property param="test" and content "someword"
page 4 have property param="test3" and content "someword"

Search:
swish-e -w "someword" -uniqlimitproperty "param"

Result:
page 1
page 2
page 4

I think it will be very useful function for grouping result with same properties!

May be in API it filter better apply after search->Execute but befor search->NextResult.