creating new PDB from PDB$SEED

Wallets always seem to not like me very much when dealing with them.

I am trying to create a PDB from PDB$SEED 12c R2
ASM so I give the below command (with correct variables) and that works fine, but I can not add new tablespaces because there is no key in the wallet for that PDB. Expected behaviour.

create pluggable database TESTPDB admin user <username> identified by <password>;

Now I need to re-assure myself that the next step is simply below (the force is apparently available since 12c R2 and negates having to close the database and open the password wallet ) I would hate to screw up the wallet somehow..even in our test system. Anyone doing this in this version of oracle regularly?
open the new pdb
switch to new PDB as SYS
ADMINISTER KEY MANAGEMENT SET KEY FORCE KEYSTORE IDENTIFIED BY "<passsword>" WITH BACKUP;

Jack van Zanen