It's possible to close off availability to OTA's but remain available on your own website. This can be done per Room type, or for All room types at once.
For each of the Rateplans that are mapped to OTA's, there is an "OTA Restrictions" row underneath the pricing. This allows you to close out rooms on a per rateplan basis - for example not selling Room Only but leaving Bed & Breakfast on open sale.
To apply the close out, click the small square under the pricing row for the room type in question. This brings up an OTA close out pop-out. Set the required date range and if the restriction is to apply to all mapped rooms, select All from the Room type drop down list. Ensure that the status is set to Unavailable and finally click the blue Update button. When the pricing screen refreshes, the small square on the pricing screen will turn yellow for all rooms and dates included in the set period. An update will automatically be pushed to all connected OTAs to close out the availability but we'd always recommend checking that this has been successfully applied on each channel.