Unfollow Everything!

I did an early spring cleaning yesterday.
Unfollowing all 3000 followees..followingers..fellowship..users I do follow.
And I had to do it by force. I did write a nice script, but that didn't work.
Instead, brute force:

from steem import Steem
from steem.commit import Commit
from steem.account import Account

username='isnochys'
s = Steem()
c = Commit(s)
aac = Account(username,s)
exp = aac.export()
fl = exp['following']
for fol in fl:
    c.unfollow(unfollow=fol, account=username)

That is a really awfull script.
But it worked.

I had something else in my mind, when I first got spring cleaning in my head:

from steem import Steem
from steem.commit import Commit
from steem.account import Account
from steem.transactionbuilder import TransactionBuilder
from steembase import operations

username='isnochys'
s = Steem()
c = Commit(s)
aac = Account(username,s)
exp = aac.export()
fl = exp['following']
unfol=[]
for fol in fl:
    required_auths=[]
    required_posting_auths =[username]
    id = 'follow'
    json = ["follow",{"follower":username,"following":fol,"what":[]}]
    mdi = {"required_auths": required_auths,'required_posting_auths':required_posting_auths,'id':id,'json':json}
    unfol.append(mdi)

tb = TransactionBuilder()
operation = [operations.CustomJson(**x) for x in unfol]
tb.appendOps(operation)
tb.appendSigner(username, 'posting')
tb.sign()
tx = tb.broadcast()

This would have been way more elegant.
But I tried and failed with:

InsufficientAuthorityError

I have no idea, why it didn't work.
I looked into steemd.py and other linked files. The unfollow command does exactly the same, as I did in the transaction builder.
Well, I got my unfollowing. It just took a bit longer.