Runing pilight script with exec Binding

after some hours of googling and trying i do have a beginner question:
I want to run a pilight script to control my power socket with openhab 2.
Openhab 2 with openhabian and pilight is runing on the same raspberry pi 3.

I saved the command to control the socket in a *.sh file: /etc/pilight/
pilight-send -p kaku_switch -i $1 -u $2 $3

I put the file to the whitelist (in different versions to be sure): /etc/openhab2/misc/exec.whitelist

./etc/pilight/ 26741594 0 -t
./etc/pilight/ 26741594 0 -f
/etc/pilight/ 26741594 0 -t
/etc/pilight/ 26741594 0 -f

Gave openhab the permission to run it:
openhabian@openhab:/etc/pilight$ sudo chown openhabian:openhabian

And created an item:
Switch FF_Bedroom_Fan "Ventilator" <fan_ceiling> (FF_Bedroom, gFan) ["Switchable"] { exec=">[ON:./etc/pilight/ 26741594 0 -t] >[OFF:./etc/pilight/ 26741594 0 -f]" }

If i now switch the item in the HABPanel i get this log:

2020-04-11 11:47:10.534 [ome.event.ItemCommandEvent] - Item ‘FF_Bedroom_Fan’ received command ON

2020-04-11 11:47:10.552 [vent.ItemStateChangedEvent] - FF_Bedroom_Fan changed from OFF to ON

2020-04-11 11:47:10.556 [GroupItemStateChangedEvent] - gFan changed from OFF to ON through FF_Bedroom_Fan

2020-04-11 11:47:11.536 [ome.event.ItemCommandEvent] - Item ‘FF_Bedroom_Fan’ received command OFF

2020-04-11 11:47:11.551 [GroupItemStateChangedEvent] - gFan changed from ON to OFF through FF_Bedroom_Fan

2020-04-11 11:47:11.562 [vent.ItemStateChangedEvent] - FF_Bedroom_Fan changed from ON to OFF

However the power socket is not triggered.
If i run the script via the ssh console it is working fine.

Also i tried creating a thing with the exec Binding, but i am not sure if it is needed and also i do not understand it and it is also not working. I dont know if i have to create a thing for turning it on and an additional for turning it off?
Also installed the transformation add-on for exec and Regex.

Can someone please help me, i am stuck there.

Thank you! Simon

I managed to control the power socket with the pilight binding now.
However i am still curious what was wrong with the exec approach.

Do a search on the forum for exec binding e.g.