Intro

VK.com does not provide a bulk mode for removing old/unneeded chats (dialogs), and deleting them one by one is too slow, as it requires confirmation on every step.
To work around this issue, I created a couple of bash (perhaps, the only thing I'm not utterly terrible at) scripts leveraging VK API.

Getting ready

Authorize the app

In order to use VK API, authorize the app I specifically created for this project.
Alternatively, create your own standalone app, replace XXXXX in the link below with the ID of your app and open the link in a browser:

https://oauth.vk.com/authorize?client_id=XXXXX&display=page&redirect_uri=https://oauth.vk.com/blank.html&scope=messages&response_type=token&v=5.76

If you see the following, log out of VK, log back in and try authorizing the app again

{"error":"invalid_request","error_description":"Security Error"}

Once the app is authorized, you will be redirected to a page with a URL such as the one below: https://oauth.vk.com/blank.html#access_token=0dba993a40a7a4ba&expires_in=86400&user_id=12345

Create a config

Clone the repo and create a configuration file based on the sample

$ cp vk.conf.sam vk.conf

Then, populate vk.conf accordingly.

Install jq

The scripts are using jq (tested with v1.3), so it must be installed and added to PATH.

Fun part

Get the list of dialogs/people

Generate vk_users_from_dialogs.csv file containing "user_id,name" pairs of people you talked to

$ ./vk_get_users_from_dialogs.sh

Group chats, bots and other special users are not included into the resulting file.

Filter the list

Edit the CSV file by leaving only those users, dialogs with whom you want to remove.

Delete the dialogs

$ ./vk_delete_dialogs_with_users.sh [FILE]

If FILE is omitted, vk_users_from_dialogs.csv will be processed.