Can a mapping conflict be resolved by deleting the old indices?

Dear community,

we have several mapping conflicts in across our indices (separated on a daily basis).

Mapping conflict! 60 fields are defined as several types (string, integer, etc) across the indices that match this pattern. You may still be able to use these conflict fields in parts of Kibana, but they will be unavailable for functions that require Kibana to know their type. Correcting this issue will require re-indexing your data.

For instance we have a field that contains a string and was later converted to a number due a problem in a logstash configuration. I have read to solve this conflict, we have use the mapping API or reindex our data with a correct mapping.

I wonder - out of curiosity - if I couldn't just delete the index with the wrong data. Wouldn't the problem go away by doing this? It seems to me that didn't work. I could need some information or confirmation, if this a valid approach or not.

My colleague claims that in Kibana 3 it did work, but in Kibana 4 it seems to me, that he still can't use this field for the visualization. Thanks in advance.