Help with converting 3 separate nodes into 3-node cluster ?

We currently have 3 hosts running 5.6.22 Percona XtraDB Cluster. These were originally in 3 node cluster, but due to very old errors they all were out of synch. I attempted to re-synch the nodes in that cluster, but gave up, due to the various errors, including not being able to start 2 of the nodes in the ‘original’ cluster mode .
And, since we could postpone the writes, I did re-synch the data via mysqldump / restore individually onto 3 nodes (each in Primary status now with wsrep_cluster_address = gcomm://).
What would be the best steps to re-join the nodes , or bootstrap these 3 hosts into one cluster again?
Thank you in advance. (Sorry, new to Percona cluster, and probably did something that is not quite correct… )