How to delete unwanted contacts from messaging

[geezerplayer]

I have a gs4 mini. I have figured out how to delete those annoying unknown contacts from your standard messaging list. Navigate as follows....
1. SETTINGS
2. DEVICE
3. ACCOUNTS
4. UNSYNC ALL ACCOUNTS......EXIT
5. HOME SCREEN
6. CONTACTS
7. ENTER THE LETTER A IN THE SEARCH FIELD
8. HOLD ON EACH UNWANTED CONTACT AND DELETE WHEN PROMPTED....ONE AT A TIME.
Still some left?
9. CLEAR SEARCH FIELD
10. ENTER ANY LETTER CONTAINED IN THE REMAINING CONTACTS.
11. CONTINUE WITH STEPS 7 and 8 UNTIL COMPLETED
Should work with any current android but specifically galaxy.
GOOD LUCK DROIDSTERS!