A contradictory statement on which to use on recursion-method for PXC between:
 
This part of the documentation where cluster method is suggested for PXC versions 5.5.29 and above:

{{The *cluster* method requires a cluster based on Galera 23.7.3 or newer, such as Percona XtraDB Cluster versions 5.5.29 and above. This will auto-discover nodes in a cluster using SHOW STATUS LIKE 'wsrep_incoming_addresses'. You can combine cluster with processlist and hosts to auto-discover cluster nodes and replicas, but this functionality is experimental.}}

https://www.percona.com/doc/percona-toolkit/LATEST/pt-table-checksum.html#cmdoption-pt-table-checksum-recursion-method

and on the PXC section, it describes some supported topology and also mentions you need to use dsn method instead of cluster:

*pt-table-checksum* works with Percona XtraDB Cluster (PXC) 5.5.28-23.7 and newer. The number of possible Percona XtraDB Cluster setups is large given that it can be used with regular replication as well. Therefore, only the setups listed below are supported and known to work. Other setups, like cluster to cluster, are not support and probably don’t work.Except where noted, all of the following supported setups require that you use the *dsn* method for --recursion-method to specify cluster nodes. Also, the lag check (see “REPLICA CHECKS”) is not performed for cluster nodes.
 

https://www.percona.com/doc/percona-toolkit/LATEST/pt-table-checksum.html#percona-xtradb-cluster

The expectation in the document should be consistent on which --recursion-method should be use for PXC.